Influence of Resistance Exercises on Infant Body Fat Composition in Overweight/Obese Women

Abstract

Influence of Resistance Exercises on Infant Body Fat Composition in Overweight/Obese Women By Jaclyn Ruemmler May, 2018 Director of Thesis: Dr. Linda May Major Department: Kinesiology PURPOSE: Research has conveyed that aerobic exercise during pregnancy is beneficial for overweight/obese women and their infants, however, resistance exercise has not been studied thoroughly in the overweight/obese population. Resistance training interventions have been conducted with normal weight pregnant women and they have been deemed safe and beneficial, therefore this intervention should be applied to the overweight/obese population. The purpose of this study is to determine the effect of resistance exercises during pregnancy on infant body composition. METHODS: Participants were randomized into two groups, resistance and non-exercising control, and trained from 16 weeks gestational age until delivery. The resistance group participated in three 50-55-minute sessions per week targeting all major muscle groups. After birth, one-month body composition measures consisted of BMI, skinfold and circumference measurements, and magnetic resonance imaging (MRI). Independent t-test were performed to determine differences between groups and like-genders. Correlation looked for relationships between infant variables and average METS, gestational weight gain (GWG), and pre-pregnancy BMI. Multiple linear regression was performed controlling for maternal BMI and infant gender; another linear regression was performed controlling for GWG, infant gender, and average METs. RESULTS: We analyzed data from women randomized to resistance exercise (n=7) or usual care controls (n=7). There was a 3.6% increase in lean mass volume for the infants of resistance exercisers compared to controls. Trends of lower subcutaneous fat volume, visceral/retro fat volume, and total fat volume were found in infants of resistance exercisers versus controls. Correlation measures conveyed a moderate positive relationship between GWG and one-month weight (p=0.09). The multiple linear regression measure determined infant gender is a significant predictor for lean mass volume (adj. R2=0.21; p=0.03) and one-month weight (adj. R2= 0.18; 0.04). CONCLUSION: The trends of higher lean mass volume with lower subcutaneous fat volume, visceral fat volume, and total fat volume in infants of resistance exercisers compared to infants of controls is promising for future investigators. Determining the direct response of resistance exercise on infant body composition from only overweight/obese mothers should be conducted to help provide more answers.